3.5. CTRP9 Inhibits ox-LDL-Induced mtROS Accumulation by Regulating Antioxidant Enzyme Expression
To explore the mechanism by which CTRP9 alleviates ox-LDL-induced VSMC-derived foam cell necroptosis, we detected the changes in mtROS and ΔΨm in each treatment group. VSMC-derived foam cells were either left untreated or treated with 10 μg/mL ox-LDL in the presence of different concentrations of CTRP9. The results revealed that CTRP9 inhibited ox-LDL-induced production of mtROS and loss of ΔΨm in a dose-dependent manner (Fig. 5a and b). To elucidate the mechanism by which CTRP9 inhibits ox-LDL-induced necroptosis of VSMC-derived foam cells, we measured the level of antioxidant enzymes using western blotting. Interestingly, ox-LDL increased the expression of some antioxidant enzymes, such as Foxo3, HO1, SOD2, and NQO1, and pretreatment with CTRP9 increased the expression of these proteins to a higher degree than that in the ox-LDL-only group (Fig. 5c and d).